<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Pdf
 * @subpackage FileParser
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: File.php 18993 2009-11-15 17:09:16Z alexander $
 */

/** Zend_Pdf_FileParserDataSource */
require_once 'Zend/Pdf/FileParserDataSource.php';


/**
 * Concrete subclass of {@link Zend_Pdf_FileParserDataSource} that provides an
 * interface to filesystem objects.
 *
 * Note that this class cannot be used for other sources that may be supported
 * by {@link fopen()} (through URL wrappers). It may be used for local
 * filesystem objects only.
 *
 * @package    Zend_Pdf
 * @subpackage FileParser
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Pdf_FileParserDataSource_File extends Zend_Pdf_FileParserDataSource
{
	/**** Instance Variables ****/


	/**
	 * Fully-qualified path to the file.
	 * @var string
	 */
	protected $_filePath = '';

	/**
	 * File resource handle .
	 * @var resource
	 */
	protected $_fileResource = null;



	/**** Public Interface ****/


	/* Concrete Class Implementation */

	/**
	 * Object constructor.
	 *
	 * Validates the path to the file, ensures that it is readable, then opens
	 * it for reading.
	 *
	 * Throws an exception if the file is missing or cannot be opened.
	 *
	 * @param string $filePath Fully-qualified path to the file.
	 * @throws Zend_Pdf_Exception
	 */
	public function __construct($filePath)
	{
		if (! (is_file($filePath) || is_link($filePath))) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception("Invalid file path: $filePath",
			Zend_Pdf_Exception::BAD_FILE_PATH);
		}
		if (! is_readable($filePath)) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception("File is not readable: $filePath",
			Zend_Pdf_Exception::NOT_READABLE);
		}
		if (($this->_size = @filesize($filePath)) === false) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception("Error while obtaining file size: $filePath",
			Zend_Pdf_Exception::CANT_GET_FILE_SIZE);
		}
		if (($this->_fileResource = @fopen($filePath, 'rb')) === false) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception("Cannot open file for reading: $filePath",
			Zend_Pdf_Exception::CANT_OPEN_FILE);
		}
		$this->_filePath = $filePath;
	}

	/**
	 * Object destructor.
	 *
	 * Closes the file if it had been successfully opened.
	 */
	public function __destruct()
	{
		if (is_resource($this->_fileResource)) {
			@fclose($this->_fileResource);
		}
	}

	/**
	 * Returns the specified number of raw bytes from the file at the byte
	 * offset of the current read position.
	 *
	 * Advances the read position by the number of bytes read.
	 *
	 * Throws an exception if an error was encountered while reading the file or
	 * if there is insufficient data to completely fulfill the request.
	 *
	 * @param integer $byteCount Number of bytes to read.
	 * @return string
	 * @throws Zend_Pdf_Exception
	 */
	public function readBytes($byteCount)
	{
		$bytes = @fread($this->_fileResource, $byteCount);
		if ($bytes === false) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception('Unexpected error while reading file',
			Zend_Pdf_Exception::ERROR_DURING_READ);
		}
		if (strlen($bytes) != $byteCount) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception("Insufficient data to read $byteCount bytes",
			Zend_Pdf_Exception::INSUFFICIENT_DATA);
		}
		$this->_offset += $byteCount;
		return $bytes;
	}

	/**
	 * Returns the entire contents of the file as a string.
	 *
	 * Preserves the current file seek position.
	 *
	 * @return string
	 */
	public function readAllBytes()
	{
		return file_get_contents($this->_filePath);
	}


	/* Object Magic Methods */

	/**
	 * Returns the full filesystem path of the file.
	 *
	 * @return string
	 */
	public function __toString()
	{
		return $this->_filePath;
	}


	/* Primitive Methods */

	/**
	 * Seeks the file read position to the specified byte offset.
	 *
	 * Throws an exception if the file pointer cannot be moved or if it is
	 * moved beyond EOF (end of file).
	 *
	 * @param integer $offset Destination byte offset.
	 * @throws Zend_Pdf_Exception
	 */
	public function moveToOffset($offset)
	{
		if ($this->_offset == $offset) {
			return;    // Not moving; do nothing.
		}
		parent::moveToOffset($offset);
		$result = @fseek($this->_fileResource, $offset, SEEK_SET);
		if ($result !== 0) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception('Error while setting new file position',
			Zend_Pdf_Exception::CANT_SET_FILE_POSITION);
		}
		if (feof($this->_fileResource)) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception('Moved beyond the end of the file',
			Zend_Pdf_Exception::MOVE_BEYOND_END_OF_FILE);
		}
	}

}
